MAYDAY Series: Ref #4 ~ Scientific Paper: Part 1 (of 2) Fetal Monitoring: Creating a Culture of Safety With Informed Choice”

by faithgibson on May 26, 2019

in Electronic Fetal Monitoring, OB Interventions: Dubious or Detrimental

 

Fetal Monitoring: Creating a Culture of Safety With Informed Choice

J Perinat Educ. 2013 Summer; 22(3): 156–165. doi: 10.1891/1058-1243.22.3.156

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4010242/ PMCID: PMC4010242

PMID: 24868127

Lisa Heelan, MSN, FNP-BC*

Abstract

The dominant culture in labor and birth is the medical model, not the midwifery model of woman-centered care. Consensus among professional and governmental groups is that, based on the evidence, intermittent auscultation is safer to use in healthy women with uncomplicated pregnancies than electronic fetal monitoring (EFM). Barriers impact the laboring woman’s ability to give informed choice regarding fetal monitoring. Lack of informed choice denies a woman her right to be in control of her birth experience, and is in opposition to a woman’s right to autonomy and self-determination.

Keywords: fetal monitoring, informed choice, autonomy, culture of safety, maternity care, childbirth education, nursing

Over the last five decades, women have been acculturated to continuous electronic fetal monitoring (EFM) during childbirth, and accept this type of labor management as part of the normal birth process (Hindley, Hinsliff, & Thomson, 2008Sandin-Bojo, Larsson, & Hall-Lord, 2008); however, not all women need EFM. 

Women with preeclampsia, type 1 diabetes, preterm birth, and suspected intrauterine fetal growth restriction have high risk conditions and should be monitored with EFM; healthy women without complications would be considered low risk and can use intermittent auscultation (American College of Obstetricians and Gynecologists [ACOG], 2009).

For AWHONN guidelines for Fetal Monitoring see: http://wwww.awhonn.org/awhonn/binary.content.do?name=Resources/Documents/pdf/5_FHM.pdf

Intermittent auscultation is a safe and acceptable fetal monitoring method that is recommended during labor with low-risk pregnancies.

Continuous EFM is associated with many known medical risks to women, without providing any benefit to the fetus in low-risk pregnancies (Alfirevic, Devane, & Gyte, 2006ACOG, 2009). An alternative option for healthy women with uncomplicated pregnancies is intermittent auscultation (IA). IA is a safe and acceptable fetal monitoring method that is recommended during labor with low-risk pregnancies (ACOG, 2009Anderson, 1994Association of Women’s Health and Obstetric and Neonatal Nurses [AWHONN], 2008National Institute of Clinical Excellence [NICE], 2007; The Royal Australian and New Zealand College of Obstetricians and Gynaecologists [RANZCOG], 2009; United States Preventative Services Task Force [USPSTF], 1996World Health Organization [WHO], 1996).

There is limited research exploring a woman’s ability to give informed choice regarding which method of fetal monitoring to use (Hindley et al., 2008O’Cathain, Thomas, Walters, Nicholl, & Kirkham, 2002). Many barriers exist preventing nurses from implementing IA during the intrapartum period (Graham, Logan, Davies, & Nimrod, 2004Lewis & Rowe, 2004Rattray, Flowers, Miles, & Clarke, 2011Regan & Liaschenko, 2007Sleutel, Schultz, & Wyble, 2007). The purpose of this article is to review the history of fetal monitoring; address factors influencing the fetal heart rate during labor; report on the different types of fetal monitoring available; discuss barriers identified in the literature inhibiting the implementation of fetal monitoring choice in childbirth; and provide suggestions to incorporate evidence-based material into childbirth classes.

OVERVIEW OF FETAL MONITORING

Although the fetal heart sound was first described in a poem in the 1600s, it was not until the mid-1800s that abnormal fetal heart rates were associated with fetal distress signifying the need for a forceps intervention (Freeman & Garite, 1981). At the time, evaluating a fetus was primarily accomplished by putting one’s ear to the maternal abdomen, or using a Laennec instrument (cylindrical in shape and similar to the Pinard) to auscultate the fetal heart rate (Freeman & Garite, 1981). The first fetal electrocardiogram (EKG) recording was in 1906 (Freeman & Garite, 1981); 50 years later, Dr. Hon from Yale University was able to identify causes of bradycardia leading to fetal distress by monitoring the fetal heart rate continuously from the maternal abdomen (Hon & Lee, 1963).

Continuous EFM was embraced by the obstetric community, including nursing (Sandelowski, 2000), even though clinical trials did not show evidence supporting its use in low-risk women when compared to IA (Banta & Thacker, 1979Dixon, 1981Haverkamp, Thompson, McFee, & Cetrulo, 1976). Over time, the cardiography machine (EFM) became smaller and less bulky, which allowed this technology to fit at the bedside more easily and be used. By 1978, EFM was in routine use in one-half of all labors (Williams & Hawes, 1979); in 2002, 85% of all women were assessed with EFM (Martin et al., 2003). Although the evidence does not support this type of technology being used in low-risk pregnancies, EFM has become a standard of care in childbirth practice for women in the United States.

Approximately 2 out of 1,000 children have cerebral palsy with the main risk factors for cerebral palsy being low birth weight, intrauterine infections, and multiple gestations.

FACTORS INFLUENCING FETAL HEART RATE CHANGES

Fetal monitoring is used to assess the adequacy of fetal oxygenation during labor (ACOG, 2009) with the goal being to prevent metabolic acidemia. Metabolic acidemia can develop over 60 min following a fetus being deprived of adequate oxygenation (Parer, King, Flanders, Fox, & Kilpatrick, 2006). 

Hypoxia during labor can be caused by compression of the umbilical cord, or in more serious cases, by decreased placental perfusion during a uterine contraction seen in late decelerations (Miller & Miller, 2012).

Metabolic acidemia is associated with increased rates of neonatal morbidity, specifically cerebral palsy (Miller & Miller, 2012Parer et al., 2006); however, fetal hypoxia during labor is a very rare cause of cerebral palsy (Blair & Stanley, 1988). Approximately 2 out of 1,000 children have cerebral palsy with the main risk factors for cerebral palsy being low birth weight, intrauterine infections, and multiple gestations (Odding, Roebroeck, & Stam, 2006).

Factors not directly related to hypoxia that can contribute to negative changes in fetal heart rate patterns include the presence of maternal fever and infection, medications, and hyperthyroidism (Miller & Miller, 2012). 

Maternal infection has been linked to low Apgar scores, neonatal seizures (Grether & Nelson, 1997), and cerebral palsy (Grether & Nelson, 1997Wu & Colford, 2000). 

Other causes of fetal heart rate changes include conditions involving the fetus: sleep cycle; infection; anemia; arrhythmia; preexisting neurologic injury; heart block; and congenital anomalies (Miller & Miller, 2012).

DIFFERENT TYPES OF FETAL MONITORING

Fetuses are generally monitored during labor externally from the mother’s abdomen using either a cardiotocograph machine (EFM), Pinard fetal stethoscope, or an ultrasound handheld fetal doppler (Alfirevic et al., 2006).

Continuous Electronic Fetal Monitoring

External continuous cardiotocographic monitoring (EFM) is the most common method of assessing fetuses in the United States while in labor (Martin et al., 2003), and it requires a woman to be immobile to obtain accurate readings. Two straps are placed around her abdomen, with one strap containing the Doppler ultrasound transducer to monitor the fetus’s heart rate and the other having a pressure transducer to monitor uterine contractions (Alfirevic et al., 2006). EFM is associated with high false positive rates and inconsistent fetal heart rate tracing interpretations, both of which contribute to an inability to accurately predict fetal hypoxia (Alfirevic et al., 2006Tekin et al., 2008).

Continuously monitoring the fetus during labor is associated with a significant increase in cesarean surgery, instrumental vaginal births, and maternal infection with no reduction of cerebral palsy or neonatal death when it is compared to IA (Alfirevic et al., 2006).

Although neonatal seizures are rare events (1 in 500 births), the incidence is decreased with the use of EFM, but only in high-risk pregnancies, not in uncomplicated pregnancies (Chen, Chauhan, Ananth, Vintzileos, & Abuhamad, 2011); for every 661 women who receive EFM during labor to prevent one neonatal seizure (Alfirevic et al., 2006).

Central Fetal Monitoring

Many hospitals have switched to central fetal monitoring, a type of monitoring system that allows nurses to remain at the nurses’ station to observe many fetal monitoring tracings at one time. This centralization of care runs the risk of nurses not entering a laboring woman’s room as frequently. Central fetal monitoring is expensive to set up and maintain, and has not been shown to be of benefit in comparison to EFM at the bedside (Withiam-Leitch, Shelton, & Fleming, 2006). 

In a study comparing central fetal monitoring with no central monitoring, there was a statistically significant increase in cesareans (p = .01) and operative vaginal births (p = .05) for nonreassuring fetal heart rate tracings associated with central monitoring (Weiss, Balducci, Reed, Klasko, & Rust, 1997).

The guidelines for healthy women with uncomplicated pregnancies do not recommend continuous monitoring.

Auscultation

The Pinard fetal stethoscope and the handheld Doppler are used to assess the fetus intermittently, which allows the woman to move about more freely and have more control. The Pinard fetal stethoscope was developed in the 1880s, and was in wide use in the 1950s (Hale, 2008); the handheld Doppler was developed in the 1960s (Hale, 2008). 

Both of these methods are relatively simple to use, and are commonly used during prenatal visits. The advantage of the handheld Doppler is that the woman and others in the room can also hear the fetal heart beat, whereas with the Pinard, only the clinician can hear the fetal heart sounds. Intermittent auscultation also provides the human element of touch and being cared for by a person, and not a machine.

Frequency of Monitoring

Most of the guidelines recommended by professional organizations are based on expert consensus opinion (Sholapurkar, 2010), and research that did not differentiate between low-risk and high-risk pregnancies in the same studies (AWHONN, 2008). 

This has led to policies that are NOT inconsistent and NOT based on evidence.

When using IA, two professional organizations recommend an assessment every 15 min during the active phase of the first stage of labor, and every 5 min during the second stage of labor (ACOG, 2009NICE, 2007). 

Three different professional organizations suggest an assessment every 15–30 min during the active phase of the first stage of labor (AWHONN, 2008RANZCOG, 2009Society of Obstetricians and Gynaecologists of Canada [SOGC], 2007), and every 5–15 min during the second stage (AWHONN, 2008). 

These protocols have major implications for an expected 1:1 ratio of nursing care during the active phase of the first stage of labor when IA is used.

Among professional organizations there is less disagreement regarding frequency of monitoring when IA is used in healthy women with uncomplicated pregnancies. When this method is employed, fetuses need to be assessed every 30 min during the active phase of the first stage of labor, and every 15 min during the second stage (ACOG, 2009AWHONN, 2008). The guidelines for healthy women with uncomplicated pregnancies do not recommend continuous monitoring (ACOG, 2009AWHONN, 2008). Labor support reflecting a 1:1 nurse-to-patient ratio is recommended by AWHONN (2008) for all women during the second stage of labor, regardless of the type of fetal monitoring used.

Additional Testing With EFM

Internal monitoring is added to EFM if fetal distress is suspected and includes fetal scalp blood sampling, fetal pulse oximetry, or ST segment analysis (STAN; Ayres-de-Campos, et al., 2010; East, Brennecke, King, Chan, & Colditz, 2006Kale, Chong, & Biswas, 2008Tekin et al., 2008).

Fetal blood sampling (FBS) is not a new procedure and was used in women with preeclampsia and in postterm fetuses in the 1960s to directly assess the fetus for metabolic acidosis (Saling, 1966). The problems encountered during that time are the same now, specifically, this procedure is invasive, uncomfortable for the laboring woman, requires membranes to be ruptured, and requires an adequately dilated cervix (Tekin et al., 2008).

Fetal pulse oximetry, like FBS, is used to improve the specificity of EFM (Kale et al., 2008), and when compared to EFM only, versus EFM and FBS, did have a statistically significant decrease in cesarean surgeries for nonreassuring fetal heart rate (RR 0.65, 95% CI); however, it was not beneficial in reducing cesareans when used in labors with dystocia (East, Begg, & Colditz, 2007). There were no differences in neonatal outcomes (East et al., 2006).

STAN is another adjunct to EFM when hypoxia is suspected, and it increases the identification of fetuses with metabolic acidosis (Ayres-de-Campos et al., 2010). Because of different interpretations of EFM tracings, adverse neonatal outcomes continue to occur with STAN, with no difference in the perinatal mortality rate (Ayres-de-Campos et al., 2010) or significant differences in primary outcomes (Neilson, 2012). This procedure, like FBS, is invasive, and requires passing an electrode through the woman’s cervix and applying the electrode to the fetal scalp (Neilson, 2012) with at least 20 min needed to calibrate the FHR baseline (Ayres-de-Campos et al., 2010).

Nursing and medicine should perform a test or provide a treatment to improve an outcome.

Continuous EFM is not effective in improving outcomes in healthy women with uncomplicated pregnancies, yet to try to make it more effective, additional procedures are being added to EFM, with no change in neonatal outcomes; limited benefit in decreasing the risk of a cesarean surgery when a nonreassuring FHR is noted; and increased pain and discomfort to the laboring woman.

Continued –> Link to part 2

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